The present invention generally relates to Automatic Flight Control System (AFCS) and more particularly to an electrical circuit which allows electric power to be applied to electromechanical sensors only when required for mission functions as indicated by the Engine Start switch and/or AFCS Engage switch initiation.
Conventional designs of an AFCS of an aircraft allows the application of electric power to the sensor whenever aircraft power is turned on for any ground maintenance or other checkout requirements. Consequently, any time aircraft maintenance or ground test is needed which requires the use of electrical ground power, the rate gyro sensors are activated and they run continuously and thus accumulate unnecessary operating time. Consequently, there has been a significant reduction of the useful life of the sensors used in the system. It is thus desirable to limit the power-on time to the electro-mechanical rate gyros or sensors on board the aircraft which has the direct effect of gaining a much greater useful life from the electro-mechanical sensors.